SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3bd8b41cc2a7425d078d09e9461330fda62ed2ecf9c393eee620723c22719fe' 
  AND token = 'fIze4vSVNxq0x4NAK6sve2Bj2GBUvJoNG8iGKQWEHpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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