SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0291ba6d06158cefe2b005b846ea2339ccc42ecd3f02887af471a0c5d051ff7f' 
  AND token = 'XjMdy30/C8TPlzFFPsZkzOQZQJlwtkpKLPoXfWFuVlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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