SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e4e6d863646d55d3fc3af517b49b28a59a72fbea0e1afd84d2362a9d928a1df' 
  AND token = '/X0Ho0jVdYwJruZh0I0kYQ7SMd/LTQPZRQQZ3Pzm40A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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