SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e328dc216b9bb8b8b695c6a89789db478b3a94143ede46f7db329a0cd853b7ef' 
  AND token = 'QZxMQu8u+3468dZYhvBodx33i+uQHZ4FCJE01EITdgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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