SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116c47f563045ab42b33fe9af648bbbbd479dcc9da4e021ace9ccf13b769e39c' 
  AND token = 'GHfGIEWzAUVdQ3TQIO7a5PbuY7GQa9OjEegoX7BXGow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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