Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18aa43f4edcb13e146a3a2d0b64ff97ebb8cb5ba3cb948bee9fb9d7d4b5fd617' 
  AND token = 'S/xhU3T8hrOmbfvNyC181vTlTPysj+flQGR9TfG+M6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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