SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e5a4b397687b18a22be489fb26bffe949a07b34deb4a980c9c732154cbe1c67' 
  AND token = 'dG8EsGtskuJ9fNDrrsrvWJH+zJ9y427sqjVCGOzytGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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