SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f4e47e89fd5dcbb895adc642c0caa9aa714958bf4c327aafd95924ff1c2b147' 
  AND token = '5EKoOzlfHHA6vH5BVoWgmwZxUgLjkjc1w1mq6Ks5nwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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