SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1445134abc0ce97211fb7c0fe32ecf06b478989b8b58968d37fc7a31ac3758e' 
  AND token = 'pOv2eFUD2mlyWCohzbvU9ZF5EzcqSeMGjVCfHPnqUFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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