SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28cb6f8159e0170964a551c4ebc4dd7b929ab8b8bc06480fa9d75edabafa0902' 
  AND token = 'LrFFtAvWebY0g7wEmCBpujA6ocj3YfkzKc2nxlESlXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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