SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bdf0da03ee40cf88cc917148f383916d335c67c5c4b709dc92988a85e16ec94' 
  AND token = 'luIF+TGbRXWBqpeN2NM8nvaIX5T66UposJFWFBlpfso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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