SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7161301dbf86cdf936208d70be3983b8658b7a80835defe2ab5c94a6f910f76' 
  AND token = '7UDrfPyhtoJ9xQCMrTAHDJljxtE6pDPAzItjQL9UxAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00083

JSON explain

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