SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3244fe072716ee8f9daf828d1e6b79890106f0960c7a033dc02c203ce924227e' 
  AND token = 'irozc8Ghy0w6dNrOVT0dyEQtZBeoGq5Fy+6eMaK3vuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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