SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6452358f6dbc72bb99ee4c65cf2c20e33bc17702cf6384a1a548657da9e8ca5' 
  AND token = 'GNz+llcIvuRFMxc5krbQj7PmozXQNgdPLVCYERXfxCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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