SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78ed01e9aad2f41a46fbfdf98451193b5f24655b0363a64e384f834ac4453ab2' 
  AND token = 'q2KZVnUlgzX0Q7HYp0Ei6lS6IYlhb+bNudnS1MGg6Zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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