SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '72d453ebdb65e52818cf987061b94dac9edc9593c0a24172a751205181d822e7' 
  AND token = 'boY/BLMPg1SqtccStjdjb6no1AkA8XG8CUC7n2VUvso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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