SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec6a2bff27e1dba881707d415c97a3ed9533f6ec17cca79d213de25613e2f2a5' 
  AND token = 'yUXBdqW/zd29QCN2Ykanav5hJu9uqwVOGeZ2JlZzIB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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