SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bef1099d0126faa61d3595eb54e77458e65f3816377a02c622b965ebab17a0f' 
  AND token = 'Wws+enEtQnDUt4XaibdMyv23aGTz7VYohGl3l+Xa6R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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