SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b557c4d609bcd5490cfa1a42b0a19916d10ef4c477cf8fc8be4b8d9f8a8bee10' 
  AND token = 'FOg1RiSavgrdjiZFVDiL81e+fao1sI3CDFf1eYe8+Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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