SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98ff6f53c1d7a9400655ff8025ca04dbdf2fc34cc166926a5774db166a98c908' 
  AND token = '+uqzRB5sQCYkBvMnBHz+J4HHM9hJWWclO5xDiQO0XnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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