SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98679067e3d2ac4114ea0d2da1caa805d282f438a43f110936cd23759065b981' 
  AND token = 'A3dO/VlkRWZ+hYgA6czcH5J12fVkAGZiOACSVXjelvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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