SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c3914b2304ba7632f75895b9a2f70fa2a0190b5594ce088b056abeeeac59972' 
  AND token = 'V78tKgtYvttkv/BVl0youhaAgU9irS6sZE3x3zdrGt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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