SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7edfdaffc9be96cadee62b8812228889a69608ea8fc62d0b9e0b61c7da5ba363' 
  AND token = 'UfT0ILJCFhjTrwpYg1tijBA3vltT62t8zw+6h5LC4Hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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