SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3da2cc5a2622d55f7a8e17a003b7ee0504f90f610cfd6d16b818423ad0102f9f' 
  AND token = 'UQiEhM2+2fnWEXwbiegTbusDglh3YUubDL41A0+/ji4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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