SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0449110562495f1212dc6c7f9c0350c9a99fb8654a03e1591ce02c412d07785' 
  AND token = 'GiGAj7tMJptu80Yiij9wMl4/emfSfsxbLJzwH8Q4PJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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