SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '711271709cadc3d884a1878f09ca6b1064fff114cf48590dd53a6d74818f8739' 
  AND token = 'F3jFIFlzCOfP4Eqxum1pIaTte6FKuMVyCtdDgH1cwCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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