SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '679aceb7b1143a917484b533867b73e2f3c8023fdcd2ea9b03a286f40e26630e' 
  AND token = 'GDbQtU4EJai3AdpIYL5tkEngpX9QqHNodwoWZUajLsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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