SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf4f07c86e6515e4e153c5f6b0605f3623115420521c5fe4bc718e426546ddb3' 
  AND token = 'yxhz7kyJnf4mj1giEEiptJTrpcVyRmfkbiSoltszNPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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