SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '872be9bcebdc89a1fdf985788aa894fc8278234dcf23790cc941ec8fe46b2b01' 
  AND token = 'Mp4L6kpnIgMDexq08zpgB8fl1rQcoKMZ2vACVlxn1Bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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