SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '080774f224df4413556b2fcda6d08babe3340813f663946299da6ba442bda721' 
  AND token = 'KV3pfJIjrPQn4IAg2oYbjLL/8BORGe7zM1J1irJIRrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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