SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f8d499d27a7f1308528f2b0594489212cefe8333c46cc0024f7b91174b56ad' 
  AND token = 'pIUuYpsPC5LHhGh4o7vn8CJ4sOD/e4cRGhpweiwb+2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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