SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a4198e5be8ed70898fb41805b4a74f622c37e55a9ca129c3a44a3790ff34e24' 
  AND token = '5Bbd7hyW+cgrvrjohlhNJsIBNE1rLCNVf5cV7kDvus8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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