Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ce68993c607ad55358c9ee4ea0bb5e1b5cf215b9c8cdc6340ba4931e72f57a93' 
  AND token = 'hKrz7JYqi2XonmRKWwp2FiDu07KddzhlWeA71GEAHSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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