SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d26466f040393f8437f8f9ddff2eb1fefb682aba4b8c1f5dce0272512d244b7' 
  AND token = 'S4W6Ryp/4jsT13D/CZxWhPBZwPpCo5Ds8b0U0wmoMZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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