SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '302b0e2347c7aab60e78677f6c7ab416c057b2dcb09c8d7b07b23c9933c4b515' 
  AND token = 'eEWpua2/F5/0Ilv42dIBixNc0I5Bk9ubgX8CKLywkwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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