SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4e16e61aba6a094cd993fad51c951b6feccd9769d8ec2dcdb89719e41cd7078' 
  AND token = 'ehkGfzoQqJSiem1iUl6B6T6bCMXHtW6zplkaCEMBzZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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