SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aa8cef29395c07505c993e10b045bda21eb722613a937656495683c1f4b14ad' 
  AND token = 'UWdNtnusUn7l3UWZuJkKzqxT9qGW5v+Ws3GsH+m/jWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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