SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '088027d03f98ac92b64e94715d583d109d836ddf472614939e48cba6b1e13bff' 
  AND token = '9SerQlMeAaKjEpsyrGAyJOPoKFt6N4LIqofnAUKoBWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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