SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e47fdcd4bc0fa044d3e273a6510007589e0acd10bb47985e43e33d3cb008825' 
  AND token = 'H53zNiB6YDzz4MgHPmBb3deh2MyX9Q7Ulp0FppZaNYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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