SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94c988ec87538b084cdd7b51b0358d43aad521579085c3e202c7c9c40343fbe3' 
  AND token = '9DXlUTB7CckrdSpGFCggJLqn/ZeGKwNh69iUuj5ZkRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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