diff --git a/plan/plans/index.go b/plan/plans/index.go
index b5e48a3e45..3ea55f87cb 100644
--- a/plan/plans/index.go
+++ b/plan/plans/index.go
@@ -402,14 +402,14 @@ func (r *indexPlan) Next(ctx context.Context) (*plan.Row, error) {
 }
 
 func (r *indexPlan) isPointLookup(span *indexSpan) bool {
-	equalOp := span.lowVal == span.highVal && !span.lowExclude && !span.highExclude
-	if !equalOp || !r.unique || span.lowVal == nil {
+	if span.lowExclude || span.highExclude || span.lowVal == nil || !r.unique {
 		return false
 	}
-	n, err := types.Compare(span.seekVal, span.lowVal)
+	n, err := types.Compare(span.seekVal, span.highVal)
 	if err != nil {
 		return false
 	}
+	// 'seekVal==highVal' means that 'seekVal==lowVal && lowVal==highVal'
 	return n == 0
 }
 
diff --git a/util/types/convert.go b/util/types/convert.go
index 711edff1fd..55ebd67486 100644
--- a/util/types/convert.go
+++ b/util/types/convert.go
@@ -336,6 +336,8 @@ func Convert(val interface{}, target *FieldType) (v interface{}, err error) {
 			return t.RoundFrac(fsp)
 		case string:
 			return mysql.ParseDuration(x, fsp)
+		case []byte:
+			return mysql.ParseDuration(string(x), fsp)
 		default:
 			return invConv(val, tp)
 		}
@@ -359,6 +361,8 @@ func Convert(val interface{}, target *FieldType) (v interface{}, err error) {
 			return t.RoundFrac(fsp)
 		case string:
 			return mysql.ParseTime(x, tp, fsp)
+		case []byte:
+			return mysql.ParseTime(string(x), tp, fsp)
 		case int64:
 			return mysql.ParseTimeFromNum(x, tp, fsp)
 		default:
@@ -407,6 +411,8 @@ func Convert(val interface{}, target *FieldType) (v interface{}, err error) {
 		switch x := val.(type) {
 		case string:
 			intVal, err = StrToInt(x)
+		case []byte:
+			intVal, err = StrToInt(string(x))
 		case mysql.Time:
 			return int64(x.Year()), nil
 		case mysql.Duration: