SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd20ce77784c4a4a49162f89c413db1dff228f7f0316874a52b50fea8026e688f' 
  AND token = 'YdLnEYNwwWhwRBgzmV+wdAqwsqXE9LpvhdAwBQK2WCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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