SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81bcd65e18231e7bf165a20845e07b1e3fcbc086377e55db2d5b554dab499619' 
  AND token = 'QXNof7C/Y+esgcD2n+5ii/IuNNPs0qeV8ddh/vc0BoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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