SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '943aad26c04f830f0c3e31ebcec4ea09a8c457ddb47e020dd09b08ae0fa59e94' 
  AND token = 'BWKDlNoWb2XSIAikUIuKUKxZr1Bc7EJBNxSzU82+hIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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