SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eeb944c988658d4720ae996f417c485bc535f2e0faa08bf8dfae960489af544' 
  AND token = 'ReRsIIYWokliiMLvk/9xjzkiEgTn61XQ2YgZ/ps9Xgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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