SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '871c08ce233fa7ccfee0e9ef2de6b0e2b31f79d35325b3f9c27bd0326d4d4185' 
  AND token = '3WAhVSTa2RrxphjfZrQFvjiSXhHYVDnqqiYUJVn+FwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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