SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71ddba81cb5f4ecf24000d9048cc085ea1254a65554c0f694166658ab965b612' 
  AND token = 'Jp1fm6QRtvUmYtcw7SKxyHSjsbSy48ghvucFqpYbFYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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