SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4e96b8662ef902d585d038e56b4e2e48daaa8794c02b3c21ebb72f66f6997d' 
  AND token = 'vKJ9h4BhhgpmX+jjOFPyZNDqc26zgKuRq4HGSyXCkEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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