SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5617d3f773f420f8bb78be1593fbc66bd6e62b00ebe7b04bd6225a677c23c184' 
  AND token = '1eQ9h28w85pVmIX1DgNAJxIN2gKuFod3/XvcVqdUiGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}