SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e59a674b1c603d8b29edd541146fb117667828363b819a352f45158ded2ea05f' 
  AND token = 'ZGcstzXoLER39q3SnkMSwfAQc9d4XoH5hMjAHWDEiRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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