SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb287bf2e945156a94be837cb297a2fc94148c470600c6937d76149db9db4be' 
  AND token = '7h6eXX4WOb/uHFdtZ2q1eX8OcNmHNUJwmEsynfZflkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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