SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0f50ae57149b9e9164a46d9364fa45e55b442315bfe17ce46005b53f90e2d6a' 
  AND token = 'A/Z6V20Bwhh/ZFpbcm4c+KgAYRftIofe1RRgoD++Lvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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