SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '889c22e3bae504d91921bc96c6fc440397f56c766f880485c231e6dd2719697a' 
  AND token = 'vNxUY+YEhvotmIZKPNAkNkAuwz9/LoecYOeeBqj8UXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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