SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8993f1cb9af825c774f43a60a36afef8b677dfef6ff2267f45d7b198721849af' 
  AND token = 'GpJOibuZXChwoHhNM/L5r3kfbANb+9+/t3da1GZWMLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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