SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22d5889f80993760f45e944e114688ff05a3bf41a5259150210e1c65096c3be3' 
  AND token = 'LcaqLXBswhISR7WFUb/ul2FJohxfvpcufOrLBkxyoao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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