SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c7e7c27d4ad11e76845def1ba762fd116cb750ffd145600b76a9551c8174a40' 
  AND token = 'LqhfoyxDL36fzYqjybXelzL7YB4EjFHUcsWOOMywRi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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