SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '042285b217c90dc313c6d3d1ba6c8551b2ad31862c0917e93d1ce756432cb342' 
  AND token = 'sOeF3j4zxmLYr5ytX0ARXw7x8WmLgCAcAiDabyqeZ6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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