SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4abc6dab9903c6675b33332c6c35a4563588188c6bc6a854b9390248269ceebf' 
  AND token = 'IBEsKf4dIXgr9Pu6qQ3LgRmkRhkJvW/FL4pw9YSSP6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}