SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '118888a0d2870ce56be310656428d535874fe9e309d47e59d4c9920bc553044c' 
  AND token = 'ewrKo+UPphNssV8nwcReEnC70OwYiyOKSv2gofDLH/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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