SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4536329fd792b3e3e13a3472884642657fcfb15b6229ad97364167774642000e' 
  AND token = '9oEULGc04r2Rksz13uIwEF83hb6yKvYego8mRm8g5c4=' 
  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"
    }
  }
}