SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd243c3701eca2828031b6f75be73fc1fe13740fa0bd054c52462fe14d9ba390' 
  AND token = 'f0shRtTIvyeCNhQvMNV/oqKwVk0r9eY4lEL/kiNw6vU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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