SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9f4d7b167dcb83b5e1d9ca0fe06287e361f13408e4bdd591039ea05d1d65766' 
  AND token = 'YMpPLLv6rYUX+KkaMrzZ5rsoVlXh8/n+XgqZyePqAlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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