SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef77c77800c75c5cb47a99967a21aa002cdbee358a4409445923426116672378' 
  AND token = 'Pqp5guywUyCmWaGgBiSCHXhg9nMQSOFGkIeWw/hbx+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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