SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6aefc71496aa72d0b3c60005d7e23410db8a833a1df227d83a15a831580a1f06' 
  AND token = 'kFXIU+YB2uXbrmcyd0IGNIkylRkWWyBYKDusGq0my3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}