SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f99566d65333b71daf14021c2d4e18e3d8868d36927adf03b7b52f1cb48498e4' 
  AND token = 'pvnudrtWl4p1HxxhteWRqqhGwlJBa4+nJ/8O5k+zKpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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