SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed37b5b789ea6d7d5a26f1f6bb9183a607cc03f4cb19be8acc3137897f4c98c3' 
  AND token = 'Tzk0u4/v6JND2rETP/wOIM2tJcwBlaKgDwqVCsZ0v+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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