SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80de9d189ee101ff7b09d3ab878caab50c462bc94b8f3976213931afeb289f1f' 
  AND token = 'kmmB/ylKN8PP2nxxT+wRyVvsgIgXhpkLdhCfzjPQzfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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