SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e75f7cc39eaf6d7802e819631f89892c1d516ac711b0ba3529e8e10c5cad4b38' 
  AND token = 'HIE2OzHQFUlyvQAzQ9g4c32gty1dp+fKoK1m0ee560A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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