SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eac2cb36dd5c63791ccaa44d808a5c04470eb57dc22d8b281c70a7105846e097' 
  AND token = '+g/s844KdBMhCeb0m5KeuBLUrsSrSMGHMK3hNCWJxG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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