SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a8e09d050746998e177803756b897119258d436c21fe8aa5d52fe224880d194' 
  AND token = 'Y+NgdFd7Fu/6ay6ZhOTUsY5OgXJnhvJe+IjLtTK0w2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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