SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5fb8efbc11a27ab5fe2e07ccc60316e693b265584a6c78c2bdc479e3764e957' 
  AND token = 'FI6ZjhEITlp7ivRh14oiVGtebSjFcQUZeV7wQWKmyXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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