SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '005af6cc1b756ba6784590dd6fe91141263c2b0b62f8aff9166980251328abe2' 
  AND token = 'Ckm8OtmIjUKSosfEYzYdGKEDIVyphSV3bk1G55ALZvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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