SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa73a381123cbad780fbfe511abfe8b512faddc28a3ac9c4781cb30a89ad7205' 
  AND token = 'Bf70zUXR0CZyyrrN6jqvj+R3zgV8U6AyeS5uJsQNitA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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