SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116932781d9e464ec4ef61121a8d9633463fe1d4d439a87556d48a8dbefdb383' 
  AND token = 'sdYrFHkiAxT37E8umLAkRk2xNzQyiEjqQz/QayaCbOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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