SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5ad2805d3f2d22de24232c7f04772f5f41680b1299e6a85aa0810cbbce69e20' 
  AND token = 'OBJq+Bdjs0nkBagXDALQXV0d43/zSPaus3DCZHjGsuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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