SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b35e7927739842dcf5cc70acd909350d81e7f0cdb89777eef71c41ca9571e5e9' 
  AND token = 'WKGUBW38UpUBpIyNAYIZmlrp/NGH4PkHaYrHpgjeVc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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