SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd48223b2dece7d6756a4ed5b2c7714f94a50098592cc46dc8d95e4bce2fbbb06' 
  AND token = '1TwV/5XPvY/WKbmLZ3XcU1Mx1mgsMtSq8fLnJBAEKsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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