SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a35ef17ad29f5b7164cd19897e092fa673827c9946fb67b13073c07b1531e4fe' 
  AND token = 'Aw/91aLjduyUuDjRuaYSLqgo/oCFKYdcdzpADfV/iyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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