SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4992abc62d8d8106fe7425ebe017719f0baf8abdfa178905fa9dc44c7ba620' 
  AND token = 'Lg3/jHzwTRqn4hxu06l2sNw+wr9jYwzh9lWCKPBPgY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}