SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00c5944c97936d8ba5bc22abf852df88b2bac388d0e4c4e7812d324bf107aa1b' 
  AND token = 'fyV41CKmWxvYrvAdxp/9GW+/hXjym48ZRustVbIZ/dE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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