SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1afadee378509a909a4850d1fc7cc2d35229e46769c00164091d666119f2dfc6' 
  AND token = 'yiij0HgMFOp8a0BDvD5OHJAM87m3vmAl2aUsdyNdy64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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