SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90b1a3ed4e270a9e8438f27dc7cfe980d6fa0aba541d18b68934e075d412b109' 
  AND token = 'TdQW6laYJl0w136Fvdh6jOgqWODkeynWNV+Bxjc0CqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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