SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f979c69cbf04c4b303c5663626230192da95d61be409742692812296e4ba131' 
  AND token = 'aMtPezI6ZF05I131L3rZK+3K4m01eW23CdjThL6G44E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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