SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf547b2f6aea7ecb95c2df6af3fa597cfc17960a23442f2fcb703a09e06702a2' 
  AND token = 'VZ/06YHgLqAr6Q8axVbCRP5SAh7ETtjFenyNmiRxRL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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