SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebfd4ea2d7cb34458014c71d4f275e0a49f68c5a41e848812d2ff32fbdb5c731' 
  AND token = 'op/DIULt4ic1B40yFInnl2bAYs3KosBMAvyT4Vb/ZE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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