SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7f00e18fe17f49d95641a9710e7ea08aced92196e4ddb04374b0386c6503b8f' 
  AND token = 'K5irOG4jhsvagNjbCTA7qHgHJgFPhDaHU+X9B0qiGYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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