SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df817610481bd04a788ab1253c27e0ea9906f08d0e9dfeff13bdb8cc98d23f94' 
  AND token = 'jZlluR9GSvwRJ0UpPM5ECC6u9KrTN7UgxgdwLyUm+/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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