SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c8e034a6afb3b0ea614212d1cf465321bedf56f0c63e102edc28db6f798cb8' 
  AND token = 'hZxlEmsIYRXeQBARJwNnNq/RZLF/l6ges+jdZ1BXSoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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